Viral Diagnostics

Advances in diagnostic testing for transplant-related infections, particularly molecular viral diagnostic assays, constitute one of the most notable changes in transplant infectious disease over the last two decades [1, 2]. This chapter discusses recent developments in diagnostics for cytomegalovirus (CMV), Epstein-Barr virus (EBV), BK virus (BKV), community respiratory viruses (CRVs), parvovirus, hepatitis viruses, HIV, and other viral agents of importance in solid organ and hematopoietic stem cell transplantation. The recent debate regarding the extent of nucleic acid amplification (NAT) testing for HIV, HBV, and HCV in proposed transplant donors is reviewed [3]. Different uses for molecular viral tests in the transplant recipient are discussed, ranging from facilitation of antiviral preventive strategies to determination of length of therapy for active infections. The advantages and disadvantages of single vs. multiplex assays are explored [2]. Challenges in this field include interlaboratory variation [4], management of false-positive and discordant test results, and need for consensus on which patients should receive which testing, at what intervals, and for what period of time. Despite these challenges, molecular viral diagnostics have clearly contributed significantly to the reduction of infectious morbidity, by enabling early diagnosis and intervention, resulting in such notable examples as the reduction in severe CMV disease [5, 6] and in kidney allograft loss due to BKV [7]. Future clinical trials in the field of transplantation should incorporate accepted definitions of infection and practices of viral monitoring for transplantassociated viruses [8]. General Considerations, Definitions, and Uses of Viral Diagnostic Tests